The invention relates to a contact-making apparatus for electrical connection of a unit under test to an electrical test device. The contact making apparatus has a plurality of electrical test contacts, which are associated with at least one holding element, for making contact with the unit under test. The contact making apparatus has an adapter device for increasing the distance between adjacent contact paths, wherein the adapter device has contact elements for making touching contact with the test contacts.
A known contact-making apparatus of the type mentioned initially has a test head which has a plurality of holding elements arranged at a distance from one another. The holding elements are in the form of guide plates which have guide holes in which test contacts, which are in the form of bent wires, are inserted in a manner such that the wires can be moved longitudinally. The test contacts make touching contact with an adapter device which is used to increase the very narrow contact separation between the test contacts. That separation is predetermined by the contact separation on the unit under test. The increase of contact separation causes adjacent contact paths to be further apart from one another. For this purpose, those ends of the contact elements of the adapter device which are averted from the test head are connected to a printed circuit board. The printed circuit board is connected to an electrical test device, which performs an electrical test of the unit under test by making contact with the test contacts on the test head. This makes it possible, for example, to test wafers to be used in computer technology. Since the contact between the test contacts and the test head and the contact elements on the adapter device is made by pressing them against one another, good contact is present only when oxide layers and contamination are avoided. Copper wires are accordingly used as contact elements for the adapter device, with their contact elements being gold-plated. Despite the gold-plating, environmental influences or maintenance measures can result in the contacts not being optimal.